Scientists confident of SARS link

Julie BellSun Staff

Scientists working to identify the cause of a mysterious respiratory illness that has killed 111 people worldwide are now almost certain that it is associated with a new kind of coronavirus, a family of viruses also responsible for the common cold.

One of two groups of scientists whose findings were published online yesterday in separate New England Journal of Medicine articles also said they had found genetic evidence of the virus in some victims' stool samples.

The finding lends support to a previously advanced theory that the virus might spread via cockroaches that have had contact with sewage, said Dr. Peter B. Jahrling, a U.S. Army virologist whose Fort Detrick laboratory is working to find drugs that might be effective against the infection.

"It does give you some insight into potential transmission," Jahrling said. "If it's in stools, then it's in sewage. If it's in sewage, then you need to worry about how it's handled."

SARS is characterized by a fever over 100 degrees, a cough and in the most serious cases, pneumonia. It is thought primarily to be spread when infected people cough tiny droplets containing the virus into the air. The theory about sewage emerged when the virus appeared to spread from floor to floor to more than 250 people in the Amoy Gardens apartment building in Hong Kong.

While international groups of scientists led by the federal Centers for Disease Control and Prevention in Atlanta and the Bernhard Nocht Institute for Tropical Medicine in Hamburg, Germany, linked the disease to the coronavirus, Julie L. Gerberding, the CDC's director, said it was still too early to draw a final conclusion about the cause of severe acute respiratory syndrome.

"We are increasingly confident we are dealing with a new coronavirus," she said. But she added, "While we've seen evidence of the virus and we've seen evidence of pneumonia, we haven't seen them both in the same tissue."

Gerberding also said researchers have no evidence that feces is playing a role in transmission. Finding genetic evidence of the virus in stool samples is not the same as saying the virus was present in them, she told reporters yesterday on a conference call.

As of yesterday, SARS was suspected of sickening 166 people in 30 U.S. states, none of whom have died. Nearly all got sick after traveling in Asian countries where most of the cases have occurred. A CDC publication released yesterday said nine people in the United States believed to have the illness got it through household contact with an infected person, while three of the U.S. cases were health care workers who had treated people with SARS.

But Gerberding said yesterday that health officials are investigating to determine whether the virus may have spread for the first time in a workplace in the United States. In Florida, health investigators discovered a co-worker of a suspected SARS patient who had a respiratory illness and also placed that person on the list of suspected SARS cases.

"It is far too early to know if any of these workers have SARS," Gerberding said. But just in case, she said the CDC will post new guidance regarding SARS patients for schools and the workplace. "We are asking people to contact their clinician if they have any kind of unusual illness," she said.

The Army Medical Research Institute of Infectious Diseases laboratory in Frederick, where Jahrling is the top virologist, was in its first week of screening drugs against the virus. But Jahrling said the lab already had concluded that ribavirin, an anti-viral some doctors have been prescribing to people with SARS, doesn't work - at least not against the strain of coronavirus the lab has been using.

The laboratory also plans to test that drug and up to 2,000 others against virus isolated from three SARS patients in Canada, he said. The drug interferon is next on the list. In the laboratory, the virus grows freely in cells that don't contain interferon, leading Jahrling to say, "We have good reason to think interferon might work."